1991 300CE, 180m. I have owned the car since 112m and have only spotty service records back to 87m.

What is typical service life for fuel pumps? I am getting a funny noise from right rear after a warm startup. So far it has happened only about three times. Sounds like a dry pumping noise. The noise is brief and then goes away. Car drives pretty normal but I am having a more difficult warm start then usual. Car sometimes lugs a bit but then smoothes out.

Also is it essential to clean out the gas tank before putting in new fuel pumps? How is this done or is it a job best left to a shop?

Thanks,

glenmore
1991 300CE
1999, 2000 C280
2000 C230K